The first argument of vshrq_n_s8 needs to be a signed vector type,
but it was passed unsigned. Clang is more lax with conversion, but
gcc needs a cast.
Fix by me, tested by Masahiko Sawada
Per buildfarm members splitfin, batta, widowbird, snakefly, parula,
massasauga
Discussion: https://postgr.es/m/20240306074106.mg6w4koohdlworbs%40alap3.anarazel.de
Writing correct code using atomic variables is often difficult due
to the memory barrier semantics (or lack thereof) of the underlying
operations. This commit introduces atomic read/write functions
with full barrier semantics to ease this cognitive load. For
example, some spinlocks protect a single value, and these new
functions make it easy to convert the value to an atomic variable
(thus eliminating the need for the spinlock) without modifying the
barrier semantics previously provided by the spinlock. Since these
functions may be less performant than the other atomic reads and
writes, they are not suitable for every use-case. However, using a
single atomic operation with full barrier semantics may be more
performant in cases where a separate explicit barrier would
otherwise be required.
The base implementations for these new functions are atomic
exchanges (for writes) and atomic fetch/adds with 0 (for reads).
These implementations can be overwritten with better architecture-
specific versions as they are discovered.
This commit leaves converting existing code to use these new
functions as a future exercise.
Reviewed-by: Andres Freund, Yong Li, Jeff Davis
Discussion: https://postgr.es/m/20231110205128.GB1315705%40nathanxps13
There isn't a lot of user demand for AIX support, we have a bunch of
hacks to work around AIX-specific compiler bugs and idiosyncrasies,
and no one has stepped up to the plate to properly maintain it.
Remove support for AIX to get rid of that maintenance overhead. It's
still supported for stable versions.
The acute issue that triggered this decision was that after commit
8af2565248, the AIX buildfarm members have been hitting this
assertion:
TRAP: failed Assert("(uintptr_t) buffer == TYPEALIGN(PG_IO_ALIGN_SIZE, buffer)"), File: "md.c", Line: 472, PID: 2949728
Apperently the "pg_attribute_aligned(a)" attribute doesn't work on AIX
for values larger than PG_IO_ALIGN_SIZE, for a static const variable.
That could be worked around, but we decided to just drop the AIX support
instead.
Discussion: https://www.postgresql.org/message-id/20240224172345.32@rfd.leadboat.com
Reviewed-by: Andres Freund, Noah Misch, Thomas Munro
Commit 5579388d removed code that supplied a fallback implementation of
getaddrinfo(), which was dead code on modern systems. One tiny piece of
the removed code was still doing something useful on Windows, though:
that OS's own gai_strerror()/gai_strerrorA() function returns a pointer
to a static buffer that it overwrites each time, so it's not
thread-safe. In rare circumstances, a multi-threaded client program
could get an incorrect or corrupted error message.
Restore the replacement gai_strerror() function, though now that it's
only for Windows we can put it into a win32-specific file and cut it
down to the errors that Windows documents. The error messages here are
taken from FreeBSD, because Windows' own messages seemed too verbose.
Back-patch to 16.
Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Discussion: https://postgr.es/m/CA%2BhUKGKz%2BF9d2PTiXwfYV7qJw%2BWg2jzACgSDgPizUw7UG%3Di58A%40mail.gmail.com
Presently, all platforms implement atomic exchanges by performing
an atomic compare-and-swap in a loop until it succeeds. This can
be especially expensive when there is contention on the atomic
variable. This commit optimizes atomic exchanges on many platforms
by using compiler intrinsics, which should compile into something
much less expensive than a compare-and-swap loop. Since these
intrinsics have been available for some time, the inline assembly
implementations are omitted.
Suggested-by: Andres Freund
Reviewed-by: Andres Freund
Discussion: https://postgr.es/m/20231129212905.GA1258737%40nathanxps13
For the trivial case of iovcnt == 1, kernels are measurably slower at
dealing with the more complex arguments of preadv/pwritev than the
equivalent plain old pread/pwrite. The overheads are worth it for
iovcnt > 1, but for 1 let's just redirect to the cheaper calls. While
we could leave it to callers to worry about that, we already have to
have our own pg_ wrappers for portability reasons so it seems
reasonable to centralize this knowledge there (thanks to Heikki for this
suggestion). Try to avoid function call overheads by making them
inlinable, which might also allow the compiler to avoid the branch in
some cases. For systems that don't have preadv and pwritev (currently:
Windows and [closed] Solaris), we might as well pull the replacement
functions up into the static inline functions too.
Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi>
Discussion: https://postgr.es/m/CA+hUKGJkOiOCa+mag4BF+zHo7qo=o9CFheB8=g6uT5TUm2gkvA@mail.gmail.com
The fallback implementation of pg_atomic_test_set_flag() that uses
atomic-exchange gives pg_atomic_exchange_u32_impl() an extra
argument. This issue has been present since the introduction of
the atomics API in commit b64d92f1a5.
Reviewed-by: Andres Freund
Discussion: https://postgr.es/m/20231114035439.GA1809032%40nathanxps13
Backpatch-through: 12
* sync_method is renamed to wal_sync_method.
* sync_method_options[] is renamed to wal_sync_method_options[].
* assign_xlog_sync_method() is renamed to assign_wal_sync_method().
* The names of the available synchronization methods are now
prefixed with "WAL_SYNC_METHOD_" and have been moved into a
WalSyncMethod enum.
* PLATFORM_DEFAULT_SYNC_METHOD is renamed to
PLATFORM_DEFAULT_WAL_SYNC_METHOD, and DEFAULT_SYNC_METHOD is
renamed to DEFAULT_WAL_SYNC_METHOD.
These more descriptive names help distinguish the code for
wal_sync_method from the code for DataDirSyncMethod (e.g., the
recovery_init_sync_method configuration parameter and the
--sync-method option provided by several frontend utilities). This
change also prevents name collisions between the aforementioned
sets of code. Since this only improves the naming of internal
identifiers, there should be no behavior change.
Author: Maxim Orlov
Discussion: https://postgr.es/m/CACG%3DezbL1gwE7_K7sr9uqaCGkWhmvRTcTEnm3%2BX1xsRNwbXULQ%40mail.gmail.com
As with the Intel and Arm CRC instructions, compiler intrinsics for
them must be supported by the compiler. In contrast, no runtime check
is needed. Aligned memory access is faster, so use the Arm coding as
a model.
YANG Xudong
Discussion: https://postgr.es/m/b522a0c5-e3b2-99cc-6387-58134fb88cbe%40ymatrix.cn
MSVC's _BitScan* functions return a boolean indicating whether any
bits were set in the input, and we were previously asserting that
they returned true, per our API. This is correct. However, other
platforms simply assert that the input is non-zero, so do that to be
more consistent.
Noted while investigating a hypothesis from Ranier Vilela about
undefined behavior, but this is not his proposed patch.
Discussion: https://www.postgresql.org/message-id/CAEudQAoDhUZyKGJ1vbMGcgVUOcsixe-%3DjcVaDWarqkUg163D2w%40mail.gmail.com
The "fsync" level already flushes drive write caches on Windows (as does
"fdatasync"), so it only confuses matters to have an apparently higher
level that isn't actually different at all.
That leaves "fsync_writethrough" only for macOS, where it actually does
something different.
Reviewed-by: Magnus Hagander <magnus@hagander.net>
Discussion: https://postgr.es/m/CA%2BhUKGJ2CG2SouPv2mca2WCTOJxYumvBARRcKPraFMB6GSEMcA%40mail.gmail.com
Windows has similar functions with leading underscores. Previously, we
provided the rename via a macro in win32_port.h. In fact its functions
are not always good replacements for the Unix functions, since they
can't deal with UTF-8. They are only currently used by pg_locale.c,
which is careful to redirect to other Windows routines for UTF-8. Given
that portability hazard, it seem unlikely to be a good idea to encourage
any other code to think of these functions as being available outside
pg_locale.c. Any code that thinks it wants these functions probably
wants our wchar2char() or char2wchar() routines instead, or it won't
actually work on Windows in UTF-8 databases.
Furthermore, some major libc implementations including glibc don't have
them (they only have the standard variants without _l), so external code
is very unlikely to require them to exist.
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Discussion: https://postgr.es/m/CA%2BhUKG%2Bt_CHPzEoPnKyARJBJgE9-GxNajJo6ZuSfRK_KWFO%2B6w%40mail.gmail.com
677319746 added support for making use of MSVC's bit scanning functions.
However, that commit failed to consider 32-bit MSVC builds where the
64-bit versions of these functions are unavailable. This resulted in
compilation failures on 32-bit MSVC.
Here we adjust the code so we fall back on the manual way of finding the
bit positions for 64-bit integers when building on 32-bit MSVC.
Bug: #17967
Reported-by: Youmiu Mo
Discussion: https://postgr.es/m/17967-cd21e34a314141b2@postgresql.org
Run pgindent, pgperltidy, and reformat-dat-files.
This set of diffs is a bit larger than typical. We've updated to
pg_bsd_indent 2.1.2, which properly indents variable declarations that
have multi-line initialization expressions (the continuation lines are
now indented one tab stop). We've also updated to perltidy version
20230309 and changed some of its settings, which reduces its desire to
add whitespace to lines to make assignments etc. line up. Going
forward, that should make for fewer random-seeming changes to existing
code.
Discussion: https://postgr.es/m/20230428092545.qfb3y5wcu4cm75ur@alvherre.pgsql
This fixes many spelling mistakes in comments, but a few references to
invalid parameter names, function names and option names too in comments
and also some in string constants
Also, fix an #undef that was undefining the incorrect definition
Author: Alexander Lakhin
Reviewed-by: Justin Pryzby
Discussion: https://postgr.es/m/d5f68d19-c0fc-91a9-118d-7c6a5a3f5fad@gmail.com
Calling fseek() or ftello() on a handle to a non-seeking device such as
a pipe or a communications device is not supported. Unfortunately,
MSVC's flavor of these routines, _fseeki64() and _ftelli64(), do not
return an error when given a pipe as handle. Some of the logic of
pg_dump and restore relies on these routines to check if a handle is
seekable, causing failures when passing the contents of pg_dump to
pg_restore through a pipe, for example.
This commit introduces wrappers for fseeko() and ftello() on MSVC so as
any callers are able to properly detect the cases of non-seekable
handles. This relies mainly on GetFileType(), sharing a bit of code
with the MSVC port for fstat(). The code in charge of getting a file
type is refactored into a new file called win32common.c, shared by
win32stat.c and the new win32fseek.c. It includes the MSVC ports for
fseeko() and ftello().
Like 765f5df, this is backpatched down to 14, where the fstat()
implementation for MSVC is able to understand about files larger than
4GB in size. Using a TAP test for that is proving to be tricky as
IPC::Run handles the pipes by itself, still I have been able to check
the fix manually.
Reported-by: Daniel Watzinger
Author: Juan José Santamaría Flecha, Michael Paquier
Discussion: https://postgr.es/m/CAC+AXB26a4EmxM2suXxPpJaGrqAdxracd7hskLg-zxtPB50h7A@mail.gmail.com
Backpatch-through: 14
Open long-lived data and WAL file descriptors with O_CLOEXEC. This flag
was introduced by SUSv4 (POSIX.1-2008), and by now all of our target
Unix systems have it. Our open() implementation for Windows already had
that behavior, so provide a dummy O_CLOEXEC flag on that platform.
For now, callers of open() and the "thin" wrappers in fd.c that deal in
raw descriptors need to pass in O_CLOEXEC explicitly if desired. This
commit does that for WAL files, and automatically for everything
accessed via VFDs including SMgrRelation and BufFile. (With more
discussion we might decide to turn it on automatically for the thin
open()-wrappers too to avoid risk of missing places that need it, but
these are typically used for short-lived descriptors where we don't
expect to fork/exec, and it's remotely possible that extensions could be
using these APIs and passing descriptors to subprograms deliberately, so
that hasn't been done here.)
Do the same for sockets and the postmaster pipe with FD_CLOEXEC. (Later
commits might use modern interfaces to remove these extra fcntl() calls
and more where possible, but we'll need them as a fallback for a couple
of systems, so do it that way in this initial commit.)
With this change, subprograms executed for archiving, copying etc will
no longer have access to the server's descriptors, other than the ones
that we decide to pass down.
Reviewed-by: Andres Freund <andres@anarazel.de> (earlier version)
Discussion: https://postgr.es/m/CA%2BhUKGKb6FsAdQWcRL35KJsftv%2B9zXqQbzwkfRf1i0J2e57%2BhQ%40mail.gmail.com
To allow testing for general support for fast bitscan intrinsics,
add symbols HAVE_BITSCAN_REVERSE and HAVE_BITSCAN_FORWARD.
Also do related cleanup in AllocSetFreeIndex(): Previously, we
tested for HAVE__BUILTIN_CLZ and copied the relevant internals of
pg_leftmost_one_pos32(), with a special fallback that does less
work than the general fallback for that function. Now that we have
a more general test, we just call pg_leftmost_one_pos32() directly
for platforms with intrinsic support. On gcc at least, there is no
difference in the binary for non-assert builds.
Discussion: https://www.postgresql.org/message-id/CAFBsxsEPc%2BFnX_0vmmQ5DHv60sk4rL_RZJ%2BMD6ei%3D76L0kFMvA%40mail.gmail.com
We'd like to use precompiled headers on windows to reduce compile times. Right
now we rely on defining UMDF_USING_NTSTATUS before including postgres.h in a few
select places - which doesn't work with precompiled headers. Instead define
it globally.
When UMDF_USING_NTSTATUS is defined we need to explicitly include ntstatus.h,
winternl.h to get a comparable set of symbols. Right now these includes would
be required in a number of non-platform-specific .c files - to avoid that,
include them in win32_port.h. Based on my measurements that doesn't increase
compile times measurably.
Reviewed-by: Thomas Munro <thomas.munro@gmail.com>
Discussion: https://postgr.es/m/20220927011951.j3h4o7n6bhf7dwau@awork3.anarazel.de
Commits cf112c12 and a0dc8271 were a little too hasty in getting rid of
the pg_ prefixes where we use pread(), pwrite() and vectored variants.
We dropped support for ancient Unixes where we needed to use lseek() to
implement replacements for those, but it turns out that Windows also
changes the current position even when you pass in an offset to
ReadFile() and WriteFile() if the file handle is synchronous, despite
its documentation saying otherwise.
Switching to asynchronous file handles would fix that, but have other
complications. For now let's just put back the pg_ prefix and add some
comments to highlight the non-standard side-effect, which we can now
describe as Windows-only.
Reported-by: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
Reviewed-by: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
Discussion: https://postgr.es/m/20220923202439.GA1156054%40nathanxps13
Visual Studio 2015+ has support for a macro to control the alignement of
structures as of __declspec(align(#)), and this commit adds a definition
of pg_attribute_aligned() based on that. It happens that this was
already used in the implementation of atomics for MSVC. Note that there
is still no definition fo pg_attribute_packed(), so this does not impact
itemptr.h.
Author: James Coleman
Discussion: https://postgr.es/m/CAAaqYe-HbtZvR3msoMtk+hYW2S0e0OapzMW8icSMYTMA+mN8Aw@mail.gmail.com
NEON support is required on the Aarch64 architecture for standard
implementations. Hardware designers for specialized markets can choose
not to support it, but that's true of floating point as well, which
we assume is supported. As with x86, some SIMD support is available
on 32-bit platforms, but those are not interesting from a performance
standpoint and would require an inconvenient runtime check.
Nathan Bossart
Reviewed by John Naylor, Andres Freund, Thomas Munro, and Tom Lane
Discussion: https://www.postgresql.org/message-id/flat/CAFBsxsEyR9JkfbPcDXBRYEfdfC__OkwVGdwEAgY4Rv0cvw35EA%40mail.gmail.com#aba7a64b11503494ffd8dd27067626a9
Per flame graph from Jelte Fennema, COPY FROM ... USING BINARY shows
input validation taking at least 5% of the profile, so it's worth trying
to be more efficient here. With this change, validation of pure ASCII is
nearly 40% faster on contemporary Intel hardware. To make this change
legible and easier to adopt to additional architectures, use helper
functions to abstract the platform details away.
Reviewed by Nathan Bossart
Discussion: https://www.postgresql.org/message-id/CAFBsxsG%3Dk8t%3DC457FXnoBXb%3D8iA4OaZkbFogFMachWif7mNnww%40mail.gmail.com
Commit 5579388d was confused about why gai_strerror() didn't work, and
used gai_strerrorA(). It turns out that we had explicitly undefined
Windows' own macro for that somewhere else. Get rid of all that, and
use the system headers' definition of gai_sterror() directly as
intended.
Discussion: https://postgr.es/m/CA+hUKGKErNfhmvb_H0UprEmp4LPzGN06yR2_0tYikjzB-2ECMw@mail.gmail.com
SUSv3, all targeted Unixes and modern Windows have getaddrinfo() and
related interfaces. Drop the replacement implementation, and adjust
some headers slightly to make sure that the APIs are visible everywhere
using standard POSIX headers and names.
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CA%2BhUKG%2BL_3brvh%3D8e0BW_VfX9h7MtwgN%3DnFHP5o7X2oZucY9dg%40mail.gmail.com
Assume that we can use LWARX hint flags and the LWSYNC instruction
on any PPC machine. The check on the assembler's behavior was only
needed for Apple's old assembler, which is no longer of interest
now that we've de-supported all PPC-era versions of macOS (thanks
to them not having clock_gettime()). Also, given an up-to-date
assembler these instructions work even on Apple's old hardware.
It seems quite unlikely that anyone would be interested in running
current Postgres on PPC hardware that's so old as to not have
these instructions.
Hence, rip out associated configure test and manual configuration
options, and just use the modernized instructions all the time.
Also, update atomics/arch-ppc.h to use these instructions as well.
(It was already using LWSYNC unconditionally in another place,
providing further proof that nobody is using PG on hardware old
enough to have a problem with that.)
Discussion: https://postgr.es/m/166622.1660323391@sss.pgh.pa.us
<sys/resource.h> is in SUSv2 and is on all targeted Unix systems. We
have a replacement for getrusage() on Windows, so let's just move its
declarations into src/include/port/win32/sys/resource.h so that we can
use a standard-looking #include. Also remove an obsolete reference to
CLK_TCK. Also rename src/port/getrusage.c to win32getrusage.c,
following the convention for Windows-only fallback code.
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CA%2BhUKG%2BL_3brvh%3D8e0BW_VfX9h7MtwgN%3DnFHP5o7X2oZucY9dg%40mail.gmail.com
<sys/un.h> is in SUSv3 and every targeted Unix has it. Some Windows
tool chains may still lack the approximately equivalent header
<afunix.h>, so we already defined struct sockaddr_un ourselves on that
OS for now. To harmonize things a bit, move our definition into a new
header src/include/port/win32/sys/un.h.
HAVE_UNIX_SOCKETS is now defined unconditionally. We migh remove that
in a separate commit, pending discussion.
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/CA%2BhUKG%2BL_3brvh%3D8e0BW_VfX9h7MtwgN%3DnFHP5o7X2oZucY9dg%40mail.gmail.com
<sys/uio.h> is in SUSv2, and all targeted Unix system have it, so we
might as well drop the probe (in fact we never really needed this one).
It's where struct iovec is defined, and as a common extension, it's also
where non-standard preadv() and pwritev() are declared on systems that
have them.
We should also be able to assume that IOV_MAX is defined on Unix.
To spell out what our pg_iovec.h header does for the OSes in the build
farm as of today:
Windows: our own struct and functions
Solaris, Cygwin: <sys/uio.h>'s struct, our own functions
Every other Unix: <sys/uio.h>'s struct and functions
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CA%2BhUKG%2BL_3brvh%3D8e0BW_VfX9h7MtwgN%3DnFHP5o7X2oZucY9dg%40mail.gmail.com
Use SSE2 intrinsics to speed up the search, where available. Otherwise,
use a simple 'for' loop. The motivation to add this now is to speed up
XidInMVCCSnapshot(), which is the reason only unsigned 32-bit integer
arrays are optimized. Other types are left for future work, as is the
extension of this technique to non-x86 platforms.
Nathan Bossart
Reviewed by: Andres Freund, Bharath Rupireddy, Masahiko Sawada
Discussion: https://postgr.es/m/20220713170950.GA3116318%40nathanxps13
Previously we bothered to forward-declare struct timezone, following man
pages on typical systems, but POSIX actually says the argument (which we
ignore anyway) is void *. Drop a line.
While here, add an assertion that nobody actually uses the tzp argument.
Previously we did extra work to select between Windows APIs needed on
older releases, but now we can just use the higher resolution function
directly.
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CA%2BhUKGKwRpvGfcfq2qNVAQS2Wg1B9eA9QRhAmVSyJt1zsCN2sQ%40mail.gmail.com
There's no known supported system needing 1 argument gettimeofday()
support. The test for it was added a long time ago (92c6bf9775). Remove.
Until now we tested whether a gettimeofday() fallback is needed when
targetting windows. Which lead to the odd result that HAVE_GETTIMEOFDAY only
being defined when targetting MinGW (which has gettimeofday() since at least
2007). As the fallback is specific to msvc, remove the configure code and
rename src/port/gettimeofday.c to src/port/win32gettimeofday.c.
While at it, also remove the definition of struct timezone, a forward
declaration of the struct is sufficient.
Reviewed-By: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-By: Thomas Munro <thomas.munro@gmail.com>
Discussion: https://postgr.es/m/20220806000311.ywx65iuchvj4qn2k@awork3.anarazel.de
John Naylor
Nathan Bossart
Heikki Linnakangas
Thomas Munro
Bruce Momjian
David Rowley
Tom Lane
Peter Eisentraut
Michael Paquier
Andres Freund